Integrated Congestion Analysis and Simulation-Based Improvement of the Al-Faris Al-Arabi Roundabout Using PTV VISSIM

Rapid growth in private-vehicle use and limited upgrades to traffic infrastructure have led to chronic congestion at key intersections in Baghdad. The Al-Faris Al-Arabi Roundabout is a critical bottleneck, with long queues and unstable circulating flow during peak hours. This study applies an integrated approach that combines field traffic counts, a commuter-perception survey, and microscopic simulation using PTV VISSIM to assess existing conditions and test improvements. Baseline results show average delays of about ۸۰ s/veh, queues exceeding ۱۵۰ m, and Level of Service (LOS) D, while more than ۷۰% of surveyed users report daily delays above ۲۰ minutes and noticeable stress and health impacts. Two mitigation strategies are evaluated: a flyover connecting Al-Mansour and Al-Zaytoun Streets, and adaptive signal control at the roundabout entries. The flyover reduces delays by roughly ۱۹% and queues by ۳۸%, whereas adaptive signal control achieves delay reductions of about ۱۴.۵% and queue reductions near ۳۰%, with lower cost and faster implementation. The findings highlight the value of combining field data, user perceptions, and simulation to support congestion-mitigation decisions in rapidly developing cities like Baghdad.

کلیدواژه ها:

Traffic Congestion ، PTV VISSIM ، Roundabout ، Adaptive Signal Control ، urban mobility